记 Spring Cloud Gateway 内存溢出查询过程
环境配置：
org.springframework.boot ： 2.1.4.RELEASE org.springframework.cloud ：Greenwich.SR1事故记录：
由于网关存在 RequestBody 丢失的情况，顾采用了网上的通用解决方案，使用如下方式解决：
@Bean
public RouteLocator tpauditRoutes(RouteLocatorBuilder builder) {
return builder.routes().route("gateway-post", r -> r.order(1)
.method(HttpMethod.POST)
.and()
.readBody(String.class, requestBody -> {return true;}) # 重点在这
.and()
.path("/gateway/**")
.filters(f -> {f.stripPrefix(1);return f;})
.uri("lb://APP-API")).build();
}
测试环境，Spring Cloud Gateway 网关功能编写完成。开始进行测试环境压测。
正常采用梯度压测方式，最高用户峰值设置为400并发。经历两轮时长10分钟左右压测，没有异常情况出现。
中午吃饭时间，设置了1个小时的时间进行测试。
回来的时候系统报出如下异常
2019-08-12 15:06:07,296 1092208 [reactor-http-server-epoll-12] WARN io.netty.channel.AbstractChannelHandlerContext.warn:146 - An exception '{}' [enable DEBUG level for full stacktrace] was thrown by a user handler's exceptionCaught() method while handling the following exception:
io.netty.util.internal.OutOfDirectMemoryError: failed to allocate 16777216 byte(s) of direct memory (used: 503316487, max: 504889344)
at io.netty.util.internal.PlatformDependent.incrementMemoryCounter(PlatformDependent.java:640)
at io.netty.util.internal.PlatformDependent.allocateDirectNoCleaner(PlatformDependent.java:594)
at io.netty.buffer.PoolArena$DirectArena.allocateDirect(PoolArena.java:764)
at io.netty.buffer.PoolArena$DirectArena.newChunk(PoolArena.java:740)
at io.netty.buffer.PoolArena.allocateNormal(PoolArena.java:244)
at io.netty.buffer.PoolArena.allocate(PoolArena.java:214)
at io.netty.buffer.PoolArena.allocate(PoolArena.java:146)
at io.netty.buffer.PooledByteBufAllocator.newDirectBuffer(PooledByteBufAllocator.java:324)
at io.netty.buffer.AbstractByteBufAllocator.directBuffer(AbstractByteBufAllocator.java:185)
at io.netty.buffer.AbstractByteBufAllocator.directBuffer(AbstractByteBufAllocator.java:176)
at io.netty.buffer.AbstractByteBufAllocator.ioBuffer(AbstractByteBufAllocator.java:137)
at io.netty.channel.DefaultMaxMessagesRecvByteBufAllocator$MaxMessageHandle.allocate(DefaultMaxMessagesRecvByteBufAllocator.java:114)
at io.netty.channel.epoll.EpollRecvByteAllocatorHandle.allocate(EpollRecvByteAllocatorHandle.java:72)
at io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:793)
at io.netty.channel.epoll.AbstractEpollChannel$AbstractEpollUnsafe$1.run(AbstractEpollChannel.java:382)
at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:163)
at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:404)
at io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:315)
at io.
当时一脸懵逼，马上开始监控 Jvm 堆栈，减少jvm的内存空间，提升并发数以后，重启项目重新压测，
项目启动参数如下：
java -jar -Xmx1024M /opt/deploy/gateway-appapi/cloud-employ-gateway-0.0.5-SNAPSHOT.jar ↓↓↓↓修改为↓↓↓↓ java -jar -Xmx512M /opt/deploy/gateway-appapi/cloud-employ-gateway-0.0.5-SNAPSHOT.jar
缩减了一半内存启动，等待问题复现。等待3分钟问题再次复现，但是同时Jvm却的进行了Full GC。
EC EU OC OU MC MU CCSC CCSU YGC YGCT FGC FGCT
275456.0 100103.0 484864.0 50280.2 67672.0 64001.3 9088.0 8463.2 501 11.945 3 0.262
275968.0 25072.3 484864.0 47329.3 67672.0 63959.4 9088.0 8448.8 502 11.970 4 0.429
没错，在出现问题的时候，系统出现了Full Gc，但是OU并没有达到触发的原因。
结合日志中的 direct memory，想到了Jvm 中的堆外内存。
使用 -XX:MaxDirectMemorySize 可以进行设置 Jvm 堆外内存大小，当 Direct ByteBuffer 分配的堆外内存到达指定大小后，即触发Full GC。
该值是有上限的，默认是64M，最大为 sun.misc.VM.maxDirectMemory()。
结合所有情况，表明堆外内存使用存在内存溢出的情况。
报错内容为Netty框架，新增以下配置，开启Netty错误日志打印：
-Dio.netty.leakDetection.targetRecords=40 #设置Records 上限 -Dio.netty.leakDetection.level=advanced #设置日志级别
项目启动，没任何问题，开启压测后服务报出如下异常：
2019-08-13 14:59:01,656 18047 [reactor-http-nio-7] ERROR io.netty.util.ResourceLeakDetector.reportTracedLeak:317 - LEAK: ByteBuf.release() was not called before it's garbage-collected. See http://netty.io/wiki/reference-counted-objects.html for more information. Recent access records: #1: org.springframework.core.io.buffer.NettyDataBuffer.release(NettyDataBuffer.java:301) org.springframework.core.io.buffer.DataBufferUtils.release(DataBufferUtils.java:420) org.springframework.core.codec.StringDecoder.decodeDataBuffer(StringDecoder.java:208) org.springframework.core.codec.StringDecoder.decodeDataBuffer(StringDecoder.java:59) org.springframework.core.codec.AbstractDataBufferDecoder.lambda$decodeToMono$1(AbstractDataBufferDecoder.java:68) reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.onNext(FluxMapFuseable.java:107) reactor.core.publisher.FluxContextStart$ContextStartSubscriber.onNext(FluxContextStart.java:103) reactor.core.publisher.FluxMapFuseable$MapFuseableConditionalSubscriber.onNext(FluxMapFuseable.java:287) reactor.core.publisher.FluxFilterFuseable$FilterFuseableConditionalSubscriber.onNext(FluxFilterFuseable.java:331) reactor.core.publisher.Operators$MonoSubscriber.complete(Operators.java:1505) reactor.core.publisher.MonoCollectList$MonoBufferAllSubscriber.onComplete(MonoCollectList.java:123) reactor.core.publisher.FluxJust$WeakScalarSubscription.request(FluxJust.java:101) reactor.core.publisher.MonoCollectList$MonoBufferAllSubscriber.onSubscribe(MonoCollectList.java:90) reactor.core.publisher.FluxJust.subscribe(FluxJust.java:70) reactor.core.publisher.FluxDefer.subscribe(FluxDefer.java:54) reactor.core.publisher.MonoCollectList.subscribe(MonoCollectList.java:59) reactor.core.publisher.MonoFilterFuseable.subscribe(MonoFilterFuseable.java:44) reactor.core.publisher.MonoMapFuseable.subscribe(MonoMapFuseable.java:56) reactor.core.publisher.MonoSubscriberContext.subscribe(MonoSubscriberContext.java:47) reactor.core.publisher.MonoMapFuseable.subscribe(MonoMapFuseable.java:59) reactor.core.publisher.MonoOnErrorResume.subscribe(MonoOnErrorResume.java:44) reactor.core.publisher.MonoOnErrorResume.subscribe(MonoOnErrorResume.java:44) reactor.core.publisher.MonoPeek.subscribe(MonoPeek.java:71) reactor.core.publisher.MonoMap.subscribe(MonoMap.java:55) reactor.core.publisher.MonoFlatMap$FlatMapMain.onNext(MonoFlatMap.java:150) reactor.core.publisher.FluxContextStart$ContextStartSubscriber.onNext(FluxContextStart.java:103) reactor.core.publisher.FluxMapFuseable$MapFuseableConditionalSubscriber.onNext(FluxMapFuseable.java:287) reactor.core.publisher.FluxFilterFuseable$FilterFuseableConditionalSubscriber.onNext(FluxFilterFuseable.java:331) reactor.core.publisher.Operators$MonoSubscriber.complete(Operators.java:1505) reactor.core.publisher.MonoCollectList$MonoBufferAllSubscriber.onComplete(MonoCollectList.java:123) reactor.core.publisher.FluxMap$MapSubscriber.onComplete(FluxMap.java:136) reactor.core.publisher.FluxPeek$PeekSubscriber.onComplete(FluxPeek.java:252) reactor.core.publisher.FluxMap$MapSubscriber.onComplete(FluxMap.java:136) reactor.netty.channel.FluxReceive.terminateReceiver(FluxReceive.java:372) reactor.netty.channel.FluxReceive.drainReceiver(FluxReceive.java:196) reactor.netty.channel.FluxReceive.onInboundComplete(FluxReceive.java:337) reactor.netty.channel.ChannelOperations.onInboundComplete(ChannelOperations.java:333) reactor.netty.http.server.HttpServerOperations.onInboundNext(HttpServerOperations.java:453) reactor.netty.channel.ChannelOperationsHandler.channelRead(ChannelOperationsHandler.java:141) io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:359) io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:345) io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:337) reactor.netty.http.server.HttpTrafficHandler.channelRead(HttpTrafficHandler.java:191) io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:359) io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:345) io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:337) io.netty.channel.CombinedChannelDuplexHandler$DelegatingChannelHandlerContext.fireChannelRead(CombinedChannelDuplexHandler.java:438) io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:323) io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:297) io.netty.channel.CombinedChannelDuplexHandler.channelRead(CombinedChannelDuplexHandler.java:253) io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:359) io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:345) io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:337) io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1408) io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:359) io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:345) io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:930) io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:163) io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:677) io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:612) io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:529) io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:491) io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:905) java.lang.Thread.run(Unknown Source) #2: io.netty.buffer.AdvancedLeakAwareByteBuf.nioBuffer(AdvancedLeakAwareByteBuf.java:712) org.springframework.core.io.buffer.NettyDataBuffer.asByteBuffer(NettyDataBuffer.java:266) org.springframework.core.codec.StringDecoder.decodeDataBuffer(StringDecoder.java:207) org.springframework.core.codec.StringDecoder.decodeDataBuffer(StringDecoder.java:59) org.springframework.core.codec.AbstractDataBufferDecoder.lambda$decodeToMono$1(AbstractDataBufferDecoder.java:68) reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.onNext(FluxMapFuseable.java:107) reactor.core.publisher.FluxContextStart$ContextStartSubscriber.onNext(FluxContextStart.java:103) reactor.core.publisher.FluxMapFuseable$MapFuseableConditionalSubscriber.onNext(FluxMapFuseable.java:287) reactor.core.publisher.FluxFilterFuseable$FilterFuseableConditionalSubscriber.onNext(FluxFilterFuseable.java:331) reactor.core.publisher.Operators$MonoSubscriber.complete(Operators.java:1505) reactor.core.publisher.MonoCollectList$MonoBufferAllSubscriber.onComplete(MonoCollectList.java:123) reactor.core.publisher.FluxJust$WeakScalarSubscription.request(FluxJust.java:101) reactor.core.publisher.MonoCollectList$MonoBufferAllSubscriber.onSubscribe(MonoCollectList.java:90) reactor.core.publisher.FluxJust.subscribe(FluxJust.java:70) reactor.core.publisher.FluxDefer.subscribe(FluxDefer.java:54) reactor.core.publisher.MonoCollectList.subscribe(MonoCollectList.java:59) reactor.core.publisher.MonoFilterFuseable.subscribe(MonoFilterFuseable.java:44) reactor.core.publisher.MonoMapFuseable.subscribe(MonoMapFuseable.java:56) reactor.core.publisher.MonoSubscriberContext.subscribe(MonoSubscriberContext.java:47) reactor.core.publisher.MonoMapFuseable.subscribe(MonoMapFuseable.java:59) reactor.core.publisher.MonoOnErrorResume.subscribe(MonoOnErrorResume.java:44) reactor.core.publisher.MonoOnErrorResume.subscribe(MonoOnErrorResume.java:44) reactor.core.publisher.MonoPeek.subscribe(MonoPeek.java:71) reactor.core.publisher.MonoMap.subscribe(MonoMap.java:55) reactor.core.publisher.MonoFlatMap$FlatMapMain.onNext(MonoFlatMap.java:150) reactor.core.publisher.FluxContextStart$ContextStartSubscriber.onNext(FluxContextStart.java:103) reactor.core.publisher.FluxMapFuseable$MapFuseableConditionalSubscriber.onNext(FluxMapFuseable.java:287) reactor.core.publisher.FluxFilterFuseable$FilterFuseableConditionalSubscriber.onNext(FluxFilterFuseable.java:331) reactor.core.publisher.Operators$MonoSubscriber.complete(Operators.java:1505) reactor.core.publisher.MonoCollectList$MonoBufferAllSubscriber.onComplete(MonoCollectList.java:123) reactor.core.publisher.FluxMap$MapSubscriber.onComplete(FluxMap.java:136) reactor.core.publisher.FluxPeek$PeekSubscriber.onComplete(FluxPeek.java:252) reactor.core.publisher.FluxMap$MapSubscriber.onComplete(FluxMap.java:136) reactor.netty.channel.FluxReceive.terminateReceiver(FluxReceive.java:372) reactor.netty.channel.FluxReceive.drainReceiver(FluxReceive.java:196) reactor.netty.channel.FluxReceive.onInboundComplete(FluxReceive.java:337) reactor.netty.channel.ChannelOperations.onInboundComplete(ChannelOperations.java:333) reactor.netty.http.server.HttpServerOperations.onInboundNext(HttpServerOperations.java:453) reactor.netty.channel.ChannelOperationsHandler.channelRead(ChannelOperationsHandler.java:141) io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:359) io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:345) io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:337) reactor.netty.http.server.HttpTrafficHandler.channelRead(HttpTrafficHandler.java:191) io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:359) io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:345) io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:337) io.netty.channel.CombinedChannelDuplexHandler$DelegatingChannelHandlerContext.fireChannelRead(CombinedChannelDuplexHandler.java:438) io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:323) io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:297) io.netty.channel.CombinedChannelDuplexHandler.channelRead(CombinedChannelDuplexHandler.java:253) io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:359) io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:345) io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:337) io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1408) io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:359) io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:345) io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:930) io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:163) io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:677) io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:612) io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:529) io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:491) io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:905) java.lang.Thread.run(Unknown Source) #3: io.netty.buffer.AdvancedLeakAwareByteBuf.slice(AdvancedLeakAwareByteBuf.java:82) org.springframework.core.io.buffer.NettyDataBuffer.slice(NettyDataBuffer.java:260) org.springframework.core.io.buffer.NettyDataBuffer.slice(NettyDataBuffer.java:42) org.springframework.cloud.gateway.handler.predicate.ReadBodyPredicateFactory.lambda$null$0(ReadBodyPredicateFactory.java:102) reactor.core.publisher.FluxDefer.subscribe(FluxDefer.java:46) reactor.core.publisher.MonoCollectList.subscribe(MonoCollectList.java:59) reactor.core.publisher.MonoFilterFuseable.subscribe(MonoFilterFuseable.java:44) reactor.core.publisher.MonoMapFuseable.subscribe(MonoMapFuseable.java:56) reactor.core.publisher.MonoSubscriberContext.subscribe(MonoSubscriberContext.java:47) reactor.core.publisher.MonoMapFuseable.subscribe(MonoMapFuseable.java:59) reactor.core.publisher.MonoOnErrorResume.subscribe(MonoOnErrorResume.java:44) reactor.core.publisher.MonoOnErrorResume.subscribe(MonoOnErrorResume.java:44) reactor.core.publisher.MonoPeek.subscribe(MonoPeek.java:71) reactor.core.publisher.MonoMap.subscribe(MonoMap.java:55) reactor.core.publisher.MonoFlatMap$FlatMapMain.onNext(MonoFlatMap.java:150) reactor.core.publisher.FluxContextStart$ContextStartSubscriber.onNext(FluxContextStart.java:103) reactor.core.publisher.FluxMapFuseable$MapFuseableConditionalSubscriber.onNext(FluxMapFuseable.java:287) reactor.core.publisher.FluxFilterFuseable$FilterFuseableConditionalSubscriber.onNext(FluxFilterFuseable.java:331) reactor.core.publisher.Operators$MonoSubscriber.complete(Operators.java:1505) reactor.core.publisher.MonoCollectList$MonoBufferAllSubscriber.onComplete(MonoCollectList.java:123) reactor.core.publisher.FluxMap$MapSubscriber.onComplete(FluxMap.java:136) reactor.core.publisher.FluxPeek$PeekSubscriber.onComplete(FluxPeek.java:252) reactor.core.publisher.FluxMap$MapSubscriber.onComplete(FluxMap.java:136) reactor.netty.channel.FluxReceive.terminateReceiver(FluxReceive.java:372) reactor.netty.channel.FluxReceive.drainReceiver(FluxReceive.java:196) reactor.netty.channel.FluxReceive.onInboundComplete(FluxReceive.java:337) reactor.netty.channel.ChannelOperations.onInboundComplete(ChannelOperations.java:333) reactor.netty.http.server.HttpServerOperations.onInboundNext(HttpServerOperations.java:453) reactor.netty.channel.ChannelOperationsHandler.channelRead(ChannelOperationsHandler.java:141) io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:359) io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:345) io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:337) reactor.netty.http.server.HttpTrafficHandler.channelRead(HttpTrafficHandler.java:191) io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:359) io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:345) io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:337) io.netty.channel.CombinedChannelDuplexHandler$DelegatingChannelHandlerContext.fireChannelRead(CombinedChannelDuplexHandler.java:438) io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:323) io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:297) io.netty.channel.CombinedChannelDuplexHandler.channelRead(CombinedChannelDuplexHandler.java:253) io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:359) io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:345) io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:337) io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1408) io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:359) io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:345) io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:930) io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:163) io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:677) io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:612) io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:529) io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:491) io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:905) java.lang.Thread.run(Unknown Source)
在 #3 中，我发现了一个眼熟的类，ReadBodyPredicateFactory.java ，还记得最开始的时候使用 readbody 配置么？
这里就是进行 cachedRequestBodyObject 的写入类，
追踪一下Readbody源码
/**
* This predicate is BETA and may be subject to change in a future release. A
* predicate that checks the contents of the request body
* @param inClass the class to parse the body to
* @param predicate a predicate to check the contents of the body
* @param <T> the type the body is parsed to
* @return a {@link BooleanSpec} to be used to add logical operators
*/
public <T> BooleanSpec readBody(Class<T> inClass, Predicate<T> predicate) {
return asyncPredicate(getBean(ReadBodyPredicateFactory.class)
.applyAsync(c -> c.setPredicate(inClass, predicate)));
}
异步调用的 ReadBodyPredicateFactory.applyAsync() 和 错误日志中的
org.springframework.cloud.gateway.handler.predicate.ReadBodyPredicateFactory.lambda$null$0(ReadBodyPredicateFactory.java:102)
指向方法一致。查看源码102行：
Flux<DataBuffer> cachedFlux = Flux.defer(() -> Flux.just(dataBuffer.slice(0, dataBuffer.readableByteCount())) );
此处 Spring Cloud Gateway 通过 dataBuffer.slice 切割出了新的 dataBuffer，但是通过 Netty 的内存检测工具判断，此处的 dataBuffer 并没有被回收。
错误如下，日志很多容易被忽视。
ERROR io.netty.util.ResourceLeakDetector.reportTracedLeak:317 - LEAK: ByteBuf.release() was not called before it's garbage-collected. See http://netty.io/wiki/reference-counted-objects.html for more information.
找到问题那就要解决才行，尝试修改源码
@Override
@SuppressWarnings("unchecked")
public AsyncPredicate<ServerWebExchange> applyAsync(Config config) {
return exchange -> {
Class inClass = config.getInClass();
Object cachedBody = exchange.getAttribute(CACHE_REQUEST_BODY_OBJECT_KEY);
Mono<?> modifiedBody;
// We can only read the body from the request once, once that
// happens if we
// try to read the body again an exception will be thrown. The below
// if/else
// caches the body object as a request attribute in the
// ServerWebExchange
// so if this filter is run more than once (due to more than one
// route
// using it) we do not try to read the request body multiple times
if (cachedBody != null) {
try {
boolean test = config.predicate.test(cachedBody);
exchange.getAttributes().put(TEST_ATTRIBUTE, test);
return Mono.just(test);
} catch (ClassCastException e) {
if (LOGGER.isDebugEnabled()) {
LOGGER.debug("Predicate test failed because class in predicate "
+ "does not match the cached body object", e);
}
}
return Mono.just(false);
} else {
// Join all the DataBuffers so we have a single DataBuffer for
// the body
return DataBufferUtils.join(exchange.getRequest().getBody()).flatMap(dataBuffer -> {
// Update the retain counts so we can read the body twice,
// once to parse into an object
// that we can test the predicate against and a second time
// when the HTTP client sends
// the request downstream
// Note: if we end up reading the body twice we will run
// into
// a problem, but as of right
// now there is no good use case for doing this
DataBufferUtils.retain(dataBuffer);
// Make a slice for each read so each read has its own
// read/write indexes
Flux<DataBuffer> cachedFlux = Flux
.defer(() -> Flux.just(dataBuffer.slice(0, dataBuffer.readableByteCount())));
ServerHttpRequest mutatedRequest = new ServerHttpRequestDecorator(exchange.getRequest()) {
@Override
public Flux<DataBuffer> getBody() {
return cachedFlux;
}
};
# 新增如下代码
DataBufferUtils.release(dataBuffer);
return ServerRequest.create(exchange.mutate().request(mutatedRequest).build(), messageReaders)
.bodyToMono(inClass).doOnNext(objectValue -> {
exchange.getAttributes().put(CACHE_REQUEST_BODY_OBJECT_KEY, objectValue);
exchange.getAttributes().put(CACHED_REQUEST_BODY_KEY, cachedFlux);
}).map(objectValue -> config.predicate.test(objectValue));
});
}
};
}
Spring Cloud Gateway 在配置的架构中，版本为2.1.1，修改以上代码后，启动项目测试，问题没有复现，正常运行。
同样这个问题，也可以选择升级 Spring Cloud Gateway 版本，在官方2.1.2版本中，此处代码已被重构，升级后测试也完全正常。
以上为个人经验，希望能给大家一个参考，也希望大家多多支持。
